In my opinion this is a more logical way of running multiple operating systems on a host since hypervisors run the entire operating system virtually, including hardware specific code like device drivers.

It's much more logical to merely run the operating system core as a user space library enabling you to run its binaries without needing to emulate hardware. I do wonder whether you can run everything that the guest system offers, such as hardware graphics acceleration.

Another drawback is that it depends on operating system vendors making available their core OS components as a library. This is especially a problem for closed-source vendors like Microsoft who may not want to do this for strategic business reasons.